Door-check.



D. E. WILLARD.

DOOR CHECK.

APPLICATION FILED MAR. 22, I915- zgmma m. Patented May 18,1915.

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DONALD E. WILLARD, 0F DANVILLE, ILLINOIS.

DOOR-CHECK.

Specification of Letters Patent.

Patented May 18, 1915..

Application filed March 22, 1915. Serial No. 16,017.

To alt whom it may concern 7 Be it known that I, DONALD E. WILLARD,

a citizen of the United States, and resident of Danville, in the countyof Vermilion and State of Illinois, have invented certain new and usefulImprovements in Door-Checks, of which the following is a specification.v My invention relates to door checks, and has particular reference toan improvement on the construction shown and described in my co-pendingapplication, Serial No. 84l5,131.

The object in the construction of the present check is to provide meanswhereby it will be impossible for the entire elimination of the checkingeffect under any circumstances.

It is not uncommon, under certain conditions, for a user to adjust thecontrol valve, then, when the conditions have changed, to find that thedoor will be closed with much force and the glass broken. If the door isarranged to be closed without wind pressure and an unusual conditionshould arise in which the wind is directed against the door, the closingaction would occur with considerable force. I have obviated any suchpossibility in the present construction, the arrangement being such thatunder no possible adjustment of the valve will the door be permitted toclose without such checking eflect as will obviate the possibility ofbreak age. This means which I have provided will not interfere with theusual operation of the check and acts simply as a safety feature.

The invention will be more readily understood by reference to theaccompanying drawing, in which:

Figure 1 is a longitudinal section through a door check constructed inaccordance with my invention, Fig. 2 is a fragmentary view similar toFig. 1 showing the piston in such position that the escape of liquidfrom one side of the piston to the other is momentarily checked, andFig. 3 is a section on the line 33 of Fig. 1. v

Referring more particularly to the drawings, it will be seen that Iprovide a casing or cylinder 10 having a bypass 11 therein, the openingsto the bypass consisting in the ports 12, 13. The by-pass is controlledby a valve 14. Mounted within the casing is a transverse shaft 15 havinga bearing in the threaded plugs 16. Secured to the shaft are arms 17 18,19, of different lengths, the intermediate arm 18 being shorter than thearm 17 and no longer than the arm 19. These arms cooperate with notches20, 21, 22 in a rack 23, which acts also as the stem of a piston 24. Acoil spring 25 surrounds the stem and bears against the piston, thespring finding a bearing at its opposite end on a Wall 26, formed as apart of a shell 27, which is fitted within the casing and acts as aguide for the rear end of the stem or rack 23. This shell is held inplace by means of a nut 28, the cylinder being closed by the cap 29. Arod 30 projects from end to end of the cylinder on the interior thereof,such rod, as best shown in Figs. 1 and 2 having a portion between thepoints 31, 32 which is of reduced diameter and is tapered, the greatestdepth of the reduced portion being at the point 31, the depth beinglessened to the point 32 where the rod resumes its normal diameter. Thisrod extends through an aperture 32 in the piston and fits such openingclosely at the point where the rod is of its normal diameter. However,when the piston is in a position between the points 31, 32 the checkingliquid will escape around the reduced portion of the rod. Likewise,after the piston passes the port 13, liquid will escape through thebypass 11, as permitted by the valve 14. However, it will be seen, uponreference to Fig. 2 that there is a point at which the passage throughthe piston and the port 13 are both closed and that the escape of liquidis momentarily stopped. Due to the slight leakage at the differentpoints, such as around the piston, through the check valve 33, etc.,this checking effect, due to the closing of all of the escape apertures,will be only momentarily, the normal action being resumed after thepiston opens a portion of the port 13.

It is believed the construction here described will be found ofimportance, in that it provides against damage due to unskilledmanipulation of the valve 14:. The location of the port 13 and the endof the taper 32 on the rod will be fixed according to diiferent designs,it being desirable, however, that these two points should be fixed inorder that the door cannot acquire a great momentum after the checkingefi'ect secured thereby is applied.

I claim:

1. In a checking device, the combination of a casing having a by-pass, apiston having a relief opening, and a tapered controlling valve passingthrough the "relief opening, said relief opening and by-pass'be' ing soarranged that both thereof are closed in one position of said asdescribed. I

2. In a checking device, the combination of a cylinder having a bypass,one entrance to Which is Within the length of the cylinder, a piston insaid cylinder adapted to cover and uncover said entrance, said pistonhaving a relief port, means for varying the area of said relief port indifferent positions of said piston, said relief port being entirelyclosed at a point in the travel of the piston Which immediately precedesthe uncovering of said entrance, substantially as described.

3. In a checking device, the combination of a cylinder having a bypass,one entrance piston, substantially Copies of this patent may be obtainedfor five cents each, by addressing the Commissioner or Patents,

to which is within the length" time cylin= der, a piston arranged tocover and uncover said entrance, said piston having an aperture, atapered rod in said cylinder and mounted in the aperture in said piston,said rod in its untapered portion substantially closing the diameter 0said rod and said entrance being so positioned that said piston at oneposition thereof may'c'lose said entrance and be positioned on a portionof the full diameter of said rod, substantially as described. 7

Signed at Chicago, Illinois, this 18th day of March, 1915. 1 r

I DONALD E. WILLARD. Witnesses:

C. F. MOONEY, T. D. BUTLER.

Washington, D. G."

ortthrough said piston, the full

